Control device



19, 1964 M. J. CAPARONE ETAL 3,133,556

CONTROL DEVICE 2 Sheets-Sheet 1 Original Filed April 7, 1959 y 19, 1964M. J. CAPARONE ET Al. 3,133,556

CONTROL DEVICE Original Filed April 7, 1959 2 Sheets-Sheet 2 UnitedStates Patent CONTROL DEVICE Michael J. Caparone, Arcadia, and TheodoreJ. Dyzkeul, Rolling Hills, Califi, assignors to Robertshaw ControlsCompany, a corporation of Delaware Continuation of application Ser. No.804,748, Apr. 7,

1959. TlllS application June 6, 1962, Ser. No. 200,473 4 Claims. (Ci.137-50539) In the past, pressure regulators have been separate unitsdisposed in the gas supply line either before or after the control whichincluded a safety pilot valve, a manual valve, and a thermostatic valve.In the case Where a separate regulator is installed upstream of thecontrol, the regulator valve approaches full closure when thethermostatic valve is closed and pilot gas only is being regulated. Whenthe thermostatic valve opens, there is a tendency for the pilot to betemporarily starved of gas before the regulator responds.

On the other hand, when a separate regulator is installed downstream ofthe control, the regulator valve is wide open when the thermostaticvalve is closed. When the thermostatic valve opens under this condition,there is an initial surge of gas to the main burner before the regulatorresumes regulation. Some attempts have been made to resolve thesedefects by incorporating the pressure regulator into the control,however, bulky and expensive controls have resulted.

An object of this invention is to position the pressure regulatordownstream from the manually operable gas cock so that pilot gas is notregulated.

Another object of this invention is to subject the regulator to inletpressure to hold the regulator valve in a closed position when thethermostatic valve is closed. thereby causing a delaying action of gasinput on the opening of the thermostatic valve to avoid an excessivesurge of gas to the main burner before the regulator resumes regulation.

Another object of this invention is to dispose a regulating spring injuxtaposed relation to the pressure regulator so as to obtain improvedregulating properties due to the use of a long, corresponding low-rate,regulating spring without increasing the dimensions of the control.Still another object of this invention is to provide a smooth-walledregulator adjustment housing having a nonrotatable adjustment memberwhereby regular response to spring adjustment is obtained.

These and other objects and advantages will become apparent from thefollowing detailed description taken in.

connection with the accompanying drawings wherein:

FIG. 1 is a front elevation of the control device embodying thisinvention with the temperature control knob removed;

FIG. 2 is a partial sectional view taken on lines IIII of FIG. 1;

FIG. 3 is a front elevation similar to FIG. 1 with the cover removed andwith the regulator lever shown in its proper position on assembly; and

FIG. 4 is an enlarged partial sectional view taken on lines IVIV of FIG.1.

In one preferred embodiment of this invention, a cas- 3,l33,556 PatentedMay 19, 1964 ing having a manually operable valve controlling fluid flowto a main burner and a pilot burner and a thermostatically operatedvalve also controlling the main burner fluid flow, is provided with apressure responsive valve regulating the fluid flow to thethermostatically operated valve. Lever means extends from the top of thepressure responsive valve to the side thereof. A pressure regulatingspring extends parallel to the pressure responsive valve and engages thelever to control the movement of the pressure responsive valve. Sincethe pressure regulating spring is parallel to the pressure responsivevalve, rather than in axial alignment therewith, a long, low-rateregulator spring may be employed to accomplish precise valve regulationwithout increasing the control thickness.

A chamber having a keyway formed in the wall thereof is provided forhousing the regulator spring. An adjustment screw is rotatably mountedin the chamber and has a movable means threadedly connected thereto. Themovable means forms a base for the free end of the regulator spring. Akey extends from the movable means and cooperates with the keyway toprevent rotation of the movable means. Hence, the movable means moveslongitudinally in response to rotation of the adjustment screw to varythe bias of the regulator spring on the lever means. Since the movablemeans merely moveslongitudinally and does not rotate, the regulatorspring is not torsionally stressed and accurate adjustment is attained.The walls of the chamber are smooth and the arrangement is such that theregulator spring is freely adjusted without snagging on irregularitiesdisposed in the chamber.

Referring more particularly to the drawings, a fluid flow control device149 having an inlet 12 and an outlet 14 is provided in the fuel supplyline of a water heater or the like. The control device 10 comprises abasic casing 16 housing the conventional control elements. Theseconventional control elements include a thermoelectrically operatedsafety valve (not shown) having a manual reset button 18, a gas cock 20,and a thermostatically operated valve 24. The gas cock 2% is providedwith a dial 22 for manual operation thereof and contains appropriateopenings for controlling fluid flow to the main burner of the waterheater and also for controlling fluid flow to a pilot burner for themain burner. The thermostatically operated valve 24 is operable betweenopen and closed positions in response to a predetermined temperaturesensed by a rod and tube assembly 26 of a type well known in the art. Amanually operable knob 28 is provided on the front of the control device10 and is rotatable to select the sensed temperature at which the valve24 will operate.

Regulating means is provided for the fluid flow between gas cock 20 andthe thermostatically operated valve 24. To this end, a subas sembly isprovided comprising a valve seat section 30 and a cover section 32. Acircular diaphragm 34 and a gasket 36 are disposed between the valveseat section 30 and the cover section 32 and a pair of screws 38 holdthe sections together to compress the gasket and the circumferentialedge of the diaphragm 34 to form a fluid-tight connection. The diaphragm34 forms a parti tion between the valve seat section 30 and the coversection 32 to define a chamber 40 above the diaphragm and a chamber 42below the diaphragm. The diaphragm 34 is of a flexible materialnon-permeable to gas and a circular diaphragm pan 44 having a smallerdiameter than the diameter of the diaphragm 34 is positioned thereabove.

A valve member 46 is provided with a circular shoulder 48 disposed onthe stem thereof and a threaded portion 50 extends from the centralportion of shoulder 48 through apertures disposed centrally in thediaphragm 34 and the diaphragm pan 44. A nut 52 is tightened on threadedportion 50 to fasten the valve member 46 to the diaphragm 34 in afluid-tight manner. The valve seat section 30 is provided with anupwardly extending hollow boss 54 and ice a circular valve seat 56 ispress-fitted thereto and staked into place. The valve seat 56 has asmaller diameter than valve member 46 and is cooperable therewith toregulate fluid flow through the control 10.

The subassembly is connected to the basic casing 16 by screws 53extending through the cover section 32 and the valve seat section 36into the basic casing 16. This aligns the passage within boss 54 with apassage 60 leading from the open end of gas cock 24). It is now apparentthat fluid flow from the gas cock 20 must flow through valve seat 56,lower chamber 42, and an opening 62 formed in the valve seat section 30adjacent boss 54 before reaching the thermostatically operated valve 24and subsequently outlet 14. A suitable gasket 64 is compressed betweenvalve seat section 30 and basic casing 16 to prevent external leakageand internal leakage between the separate passageways.

Valve seat section 30 and cover section 32 provide a housing forming asubstantially cylindrical smooth-walled adjustment chamber 66 disposedin juxtaposed relation with valve member 46 (see FIG. 4). A projectingportion 68 of the valve seat section 36 extends into a matching cavityin the basic casing 16. The projecting portion 62; is provided with acentrally disposed recess 66 and an adjustment screw 70 has one endpivotally mounted therein. The adjustment screw 70 extends along thelongitudinal axis of chamber 66 and has the other end positioned withinthe cylindrical aperture 72 formed in the cover section 32 beneath thetemperature adjustment knob 28. An annular groove is provided in theadjustment screw 70 and a sealing ring 74 is positioned therein forcooperation with the internal portion of an apertured boss 76 extendinginwardly from the cover section 32.

A first order lever 78 is provided with a semi-circular slotted end 80which aids assembly of the lever in cover section 32 to a positionwherein end 86 substantially encircles boss 76 and adjustment screw 70.A wall 82 of the cover section 32 is adapted to separate the upperdiaphragm chamber 40 from the adjustment chamber 66 and is provided withan opening 84 through which lever 78 1 extends. A substantiallytriangular-shaped member 86 is fastened to the cover section 32 bysuitable means 38 and is provided with an inwardly extending lip 96having projections which are received in edge slots 92 in lever 78 andserve as a fulcrum therefor. End 94 of lever 78 engages the threadedprojection portion 50 of valve member 46.

The slotted end 86 of lever '78 is provided with an in turned flange 96around which is mounted one end of a helical coil spring 8. The coilspring 8 is positioned about adjustment screw 70 and has the other endmounted around a centrally recessed dome 100 of an annular member 102.The peripheral edge portion 164 of annular member 102 is provided with aprojection forming a key 166 which extends into a keyway 108 formed inthe wall of adjustment member 66 and extending parallel to thelongitudinal axis thereof. The adjustment screw 70 is threadedlyreceived by the inner wall of the recessed dome 160 and is adapted tomove the annular member 102 longitudinally when the adjustment screw '70is rotated by insertion of the appropriate tool in the slot 110 providedin the end of the screw.

An annular shoulder 112 is provided on the adjustment screw 70 and isadapted to engage boss 76. When the valve seat section 30 and the coversection 32 are assembled, the adjustment screw 70 is free to rotate butthe end of the adjustment screw 70 may not be retracted from the recess69.

A C-shaped washer 114 is crimped into an annular groove formed adjacentthe end of the adjustment screw 70 and is adapted to engage the annularmember 102 to prevent further extension of coil spring 98. An imperfectthread 116 is provided at the outer extremity of the threaded portion ofthe adjustment screw 70 and is adapted to limit outward movement ofannular member 102 to prevent further compression of coil spring 98.

The valve seat section 30 is provided with a passageway 118communicating with the innermost end of adjustment chamber 66 and air isbled from chamber above diaphragm 34 through adjustment chamber 66 topassage 118 and subsequently out of a bleed connection 120 shown indotted lines at the lower right corner of FIG. 1. An appropriately-sizedorifice is drilled in the valve seat section or, alternatively, a plug(not shown) with an appropriately-sized orifice is fastened in bleedconnection 120.

A pressure tap 122 is also provided in the valve seat section 30 and isconnected to outlet 14 by means of a passageway 124 extending throughthe valve seat section 36 and the basic casing 16 to directly sense theoutlet pressure of the control 10.

In operation, gas flows from a suitable source through the inlet 12 andpast a thermoelectrically operated safety valve (not shown) to the gascock 20. The gas cock 20 is manually operated by dial 22 to control gasflow to a pilot burner through appropriate passages (not shown) and tocontrol gas flow through the end of gas cock 20 into passage 60. Gasflow into passage is then regulated by valve 46 and proceeds throughlower diaphragm chamber 42 and opening 62 to thermostatically operatedvalve 24. The thermostatically operated valve 24 is operable betweenopen and closed positions by rod and tube as sembly 26 responsive to anexternal condition, such as the temperature of water in a tank, tocontrol fluid flow through outelt 14 to a main burner (not shown)situated in heating relationship to the water tank.

The diaphragm mounted valve 46 is responsive to inlet pressure frompassage 60 and outlet pressure in the lower diaphragm chamber 42 toregulate the pressure in the control device 10 in the conventionalmanner.

Air is bled from chamber 40 above the diaphragm 34 through adjustmentchamber 66, passage 118, and bleed connection 120. The drilled orificein the valve seat section of the orificed plug (not shown) disposed inbleed connection 120 is utilized to retard the regulator response uponopening of the thermostatic valve 24 to prevent initial overgassing ofthe main burner. This orifice also provides a dampening efiect toprevent regulator vibration at low flows on low capacity burnerapplications.

The gas pressure is adjusted merely by removing the temperatureadjustment knob 28 and inserting a screw driver blade into slot 119 inadjustment screw 7 0 to rotate the same. Clockwise rotation ofadjustment screw will move the circular member 162 longitudinally towardthe cover section 32 thereby compressing regulator spring $8. Key 106disposed in keyway 10S prevents rotational movement of the circularmember 102. The bias due to compression of regulator spring 98 pivotslever 73 in a clockwise direction to move valve member 46 away fromvalve seat 56, thereby increasing the gas pressure. Since the circularmember 162 does not rotate, no torque is exerted on the regulator spring98 to erroneously vary the bias thereof. The regulator spring 93 beingmounted about inturned flange 96 on lever 78 and dome on circular member102 and the Walls of adjustment chamber 66 being smooth, the regulatorspring 98 is snagged neither on the threads of adjustment screw 70 noron irregularities in the adjustment chamber 66.

It will be noted that the regulator spring 98 extends through adjustmentchamber 66 which is parallel to and in juxtaposed relation with valvemember 46 rather than in axial alignment therewith. This insures alonger, lowrate regulator spring 98 which provides better regulationcharacteristics and more precise adjustment of the gas pressure withoutincreasing the'thickness of theintegrated control and pressure regulatorover that of prior controls without pressure regulators. Moreover, thecontrol dimensions in respect to height and width are sub stantiallyequal to such prior controls.

It will be understood that various modifications and variations, instructure as well as operation, may be ef- We claim:

l. A gaseous fuel control assembly comprising:

a pair of casing members joined together to form a hollow casing,

a flexible diaphragm secured at its periphery between said casingmembers to divide the interior of the casing into an upper and lowerchamber,

an inlet and an outlet in said lower chamber defining a passage forfluid flow through said lower chamber,

a valve element carried by the central portion of said diaphragm forcontrolling the rate of flow through said inlet,

said valve element being movable by said diaphragm in response toincreases in pressure in said lower chamber in a direction to decreasethe flow through said inlet,

a first abutment member secured to the central portion of said diaphragmon the opposite side thereof from said valve element,

means defining an adjustment chamber in said casing adjacent said upperchamber and located outside the periphery of said diaphragm,

said adjustment chamber being in communication with said upper chamber,

an adjustment member movably mounted in said adjustment chamber,

a second abutment carried by said adjustment member,

means defining a fulcrum in said upper chamber,

a lever positioned in said upper chamber with its ends disposed onopposite sides of said fulcrum,

a spring having one end engaged with said second abutment and the otherengaged with one end of said lever to bias an intermediate portion ofsaid lever into abutting pivotal engagement with said fulcrum and pivotthe other end of the lever into abutting engagement with said firstabutment member to exert a biasing force on said diaphragm in adirection to increase the flow through said inlet, said lever therebybeing held in assembled relationship with said fulcrum and abutmentmember by the reaction of said spring,

said second abutment being selectively movable by said adjustment memberto vary the biasing force on said diaphragm.

2. A gaseous fuel control assembly comprising:

a hollow casing,

a flexible diaphragm disposed in the casing dividing the interiorthereof into a pair of chambers,

an inlet and an outlet in one of said pairof chambers defining a passagefor fluid flow through said one chamber,

a valve element carried by the central portion of said diaphragm forcontrolling the rate of flow through said inlet,

said valve element being movable by said diaphragm in a direction todecrease the flow through said inlet in response to increases inpressure in said one chamber,

an adjustment chamber formed in said casing,

a Wall separating said adjustment chamber from the other of said pair ofchambers,

an opening in said wall providing communication between said otherchamber and said adjustment chamber,

means defining a fulcrum in said opening,

a first abutment secured to the central portion of said diaphragm on theopposite side thereof from said valve element,

a second abutment mounted in said adjustment chamher,

a spring having one end engaged with one of said first and secondabutments,

a lever positioned in said opening with its ends projecting into saidadjustment chamber and said other chamber with one end thereof engagedwith the other end of said spring,

said spring biasing an intermediate portion of the lever into pivotalengagement with said fulcrum pivoting the other end of the lever intoabutting engagement with the other of said first and second abutments,thereby resiliently maintaining said lever in assembled relationshipwith said fulcrum and abutments,

said spring reacting between said one of said first and second abutmentsand said lever to exert a biasing force on said diaphragm tending tomove said valve element in a direction to increase the flow through saidinlet,

and adjustment means movably mounted in said adjustment chamberselectively movable to adjust the position of said second abutment tovary the biasing force acting on said diaphragm.

3. A gaseous fuel control assembly as defined in claim 2 furtherincluding:

a keyway formed in the Wall of said adjustment cham ber with itslongitudinal axis extending substantially parallel to the direction ofmovement of said valve element,

said adjustment means comprising a threaded adjustment screw rotatablyjournalled at one end in said adjustment chamber,

said second abutment comprising an annular member threadedly mounted onsaid adjustment screw,

and a key projection formed on said annular member engaged with saidkeyway whereby rotation of said adjustment screw causes said annularmember to travel along the length of the threaded portion of saidadjustment screw.

4. A gaseous fuel control assembly as defined in claim 3 in which:

said spring comprises a coil spring surrounding the threaded portion ofsaid adjustment screw with said one end of said spring seated on saidannular member, and said one end of said lever is seated on the otherend of said spring and formed with an opening through which theadjustment screw extends,

said fulcrum comprising a lip member extending into said opening formedwith a pair of spaced projections,

and a pair of slots formed in said intermediate portion of the leverengaged with said projection.

References Cited in the file of this patent UNITED STATES PATENTS1,429,923 Bosse et a1. Sept. 26, 1922 1,525,426 Mueller et a1. Feb. 3,1925 2,022,583 Bicknell Nov. 26, 1935 2,204,060 Andersson June 11, 1940FOREIGN PATENTS 539,021 Italy Feb. 3, 1956

1. A GASEOUS FUEL CONTROL ASSEMBLY COMPRISING: A PAIR OF CASING MEMBERSJOINED TOGETHER TO FORM A HOLLOW CASING, A FLEXIBLE DIAPHRAGM SECURED ATITS PERIPHERY BETWEEN SAID CASING MEMBERS TO DIVIDE THE INTERIOR OF THECASING INTO AN UPPER AND LOWER CHAMBER, AN INLET AND AN OUTLET IN SAIDLOWER CHAMBER DEFINING A PASSAGE FOR FLUID FLOW THROUGH SAID LOWERCHAMBER, A VALVE ELEMENT CARRIED BY THE CENTRAL PORTION OF SAIDDIAPHRAGM FOR CONTROLLING THE RATE OF FLOW THROUGH SAID INLET, SAIDVALVE ELEMENT BEING MOVABLE BY SAID DIAPHRAGM IN RESPONSE TO INCREASESIN PRESSURE IN SAID LOWER CHAMBER IN A DIRECTION TO DECREASE THE FLOWTHROUGH SAID INLET, A FIRST ABUTMENT MEMBER SECURED TO THE CENTRALPORTION OF SAID DIAPHRAGM ON THE OPPOSITE SIDE THEREOF FROM SAID VALVEELEMENT, MEANS DEFINING AN ADJUSTMENT CHAMBER IN SAID CASING ADJACENTSAID UPPER CHAMBER AND LOCATED OUTSIDE THE PERIPHERY OF SAID DIAPHRAGM,SAID ADJUSTMENT CHAMBER BEING IN COMMUNICATION WITH SAID UPPER CHAMBER,AN ADJUSTMENT MEMBER MOVABLY MOUNTED IN SAID ADJUSTMENT CHAMBER, ASECOND ABUTMENT CARRIED BY SAID ADJUSTMENT MEMBER, MEANS DEFINING AFULCRUM IN SAID UPPER CHAMBER, A LEVER POSITIONED IN SAID UPPER CHAMBERWITH ITS ENDS DISPOSED ON OPPOSITE SIDES OF SAID FULCRUM, A SPRINGHAVING ONE END ENGAGED WITH SAID SECOND ABUTMENT AND THE OTHER ENGAGEDWITH ONE END OF SAID LEVER TO BIAS AN INTERMEDIATE PORTION OF SAID LEVERINTO ABUTTING PIVOTAL ENGAGEMENT WITH SAID FULCRUM AND PIVOT THE OTHEREND OF THE LEVER INTO ABUTTING ENGAGEMENT WITH SAID FIRST ABUTMENTMEMBER TO EXERT A BIASING FORCE ON SAID DIAPHRAGM IN A DIRECTION TOINCREASE THE FLOW THROUGH SAID INLET, SAID LEVER THEREBY BEING HELD INASSEMBLED RELATIONSHIP WITH SAID FULCRUM AND ABUTMENT MEMBER BY THEREACTION OF SAID SPRING, SAID SECOND ABUTMENT BEING SELECTIVELY MOVABLEBY SAID ADJUSTMENT MEMBER TO VARY THE BIASING FORCE ON SAID DIAPHRAGM.